JP Duminy and Dean Elgar built a 138-run stand as the Proteas tightened their grip in the first session of the third day against Australia at Perth.
Duminy, rapidly becoming the dominant partner, was on 74 off 141 balls and Elgar on 69 off 194 after they added 79 runs to the overnight 104-2. The Proteas, who started the day with a lead of 102, have stretched that to 181.
The incumbent batsmen did exactly what was required in the first session, staying focused and patient and leaving the ball with dedicated intent.
They had to be watchful, for some of the deliveries took off from the deck at an alarming angle, either through sheer effort, or assisted by the widening cracks. Added to that, the Australians bowled a tight line and length, but the batsmen, with time on their side, were never pressured to raise the run rate, which stood at 2.7 for the session.
Indeed, between the two of them, they found the boundary just nine times off the 26 overs bowled on Saturday morning, although Duminy took two fours off three balls from Mitchell Starc and brought up his eighth Test fifty with a wonderful straight drive off Josh Hazelwood.
The session belonged to the Proteas. Both teams knew this would be an important passage of play, but the Australians needed wickets. It was surprising that Steve Smith persisted with pace for the entire time, ignoring spinner Nathan Lyon, who could have provided at least some variation to a monochrome attack.
With that session done and dusted, the Proteas need more of the same. Ideally, they will look to bat throughout the day at the least.
What would be a decent target to offer is a difficult assessment.
Both teams will be reminded that in December 2008, South Africa achieved the second-highest successful run-chase in Test history when they reached the victory target of 414 late in the second session on the final day, for the loss of just four wickets.
And they have to factor in that they no longer have Dale Steyn in their attack, sidelined by a broken shoulder.